Analysis of the Effects of Certain Alcohol and Furan-Based Biofuels on Controlled Auto Ignition Institute for Combustion Engines, RWTH Aachen University

Format:

Conference/Event

Author/Creator:

Brassat, Brassat, author.

Contributor:

Fernandes, Ravi Xavier

Lee, Changyoul

Müther, Martin

Olivier, Herbert

Pischinger, Stefan

Thewes, Matthias

Uygun, Yasar

Conference Name:

SAE 2012 World Congress & Exhibition (2012-04-24 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2012

Summary:

For gasoline engines controlled autoignition provides the visionof enabling the fuel consumption benefit of stratified leancombustion systems without the drawback of additional NOxaftertreatment.In this study the potential of certain biofuels on thiscombustion system was assessed by single-cylinder engineinvestigations using the exhaust strategy "combustion chamberrecirculation" (CCR). For the engine testing sweeps in theinternal EGR rate with different injection strategies as well asload sweeps were performed. Of particular interest was to revealfuel differences in the achievable maximal load as well as in theNOx emission behavior. Additionally, experiments with a shocktube and a rapid compression machine were conducted in order todetermine the ignition delay times of the tested biofuelsconcerning controlled autoignition-relevant conditions. The testedbiofuels included the pure alcohols 1-Butanol and 2-Butanol as wellas the furans Tetrahydro-2-Methylfuran (2-MTHF) and 2-Methylfuran.Conventional RON 95 pump fuel and Ethanol served asstate-of-the-art non-bio and bio references.The engine tests revealed Ethanol and 2-Butanol as the biofuelswhich needed the highest rate of trapped internal residuals and areleast prone of autoignition. 1-Butanol, RON 95 pump fuel as well as2-Methylfuran show similar autoignition behavior. 2-MTHF can beauto ignited with the lowest amount of internal EGR. It could beshown that for comparable center of combustion the fuel individualnecessary internal EGR amount correlates almost linearly with itsoctane number, especially MON. Also the ignition delay measurementsare mostly in line with the engine results. All investigatedalcohol fuels reveal comparably low NOx emissions due to theirhigh enthalpy of vaporization and particularly lower adiabaticflame temperatures. E.g., Ethanol shows in contrast to theconventional RON 95 pump fuel up to 76% less NOx emissions atcomparable center of combustion. At sufficiently lean conditionsthe highest engine loads with controlled autoignition combustionare obtained with the high-knock-resistant fuels Ethanol and2-Butanol. For both fuels the maximum engine load can be enhancedby approximately 10% compared to the RON 95 pump fuel at an enginespeed of n = 1500 min-₁, whereas 2-MTHF revealed an approximately8% lower feasible maximal load

Notes:

Vendor supplied data

Publisher Number:

2012-01-1135

Access Restriction:

Restricted for use by site license